The present invention relates to an odour trap intended for installing in a pipe to a drain, which odour trap comprises a substantially tubular element which has substantially the same shape and size of flow cross-section as the pipe to the drain, and a blocking means, which blocking means, after the installing of the odour trap in the pipe, for closing the flow cross-section of the pipe to prevent fluid, preferably gas, from passing upwards in the pipe past the odour trap, runs in the flow direction downwards in the pipe from a first longitudinal wall section of the tubular element to a corresponding second longitudinal wall section thereof, which blocking means is at least partly shiftable by fluid, preferably liquid, flowing in the odour trap, in order, initially at the lowest portion of the blocking means in the flow direction, to allow the fluid, preferably liquid, to pass down downwards in the pipe past the odour trap and in order, when the fluid, preferably liquid, has passed, to return to the position which closes the flow cross-section of the pipe.
An odour trap as above is substantially previously known from U.S. Pat. No. 4,870,992 A, which discloses and describes two odour trap versions with completely different configurations and functions. The one version comprises a blocking means without a tubular element and the other a blocking means with a tubular element, in which the blocking means and the tubular element are integral. In both versions the odour trap is made of an elastically deformable material.
An odour trap of the kind indicated in the introduction is also previously known from SE 526 363 C2, in which, here again, the odour trap is integral and made of an elastically deformable material.
A problem with these known odour trap versions is, inter alia, that the active means, the blocking means, is very sensitive to external influences and that odour traps made of elastic material are difficult to fit.